package com.fang.offer.stack;

import java.util.Stack;

/**
 * <pre>
 * 题目描述
 * 用两个栈来实现一个队列，完成队列的Push和Pop操作。 队列中的元素为int类型。
 * </pre>
 *
 */
public class TwoStack {
	Stack<Integer> stack1 = new Stack<Integer>();
	Stack<Integer> stack2 = new Stack<Integer>();

	public void push(int node) {
		stack1.push(node);
	}

	public int pop() {
		if (stack2.empty()) {
			while (!stack1.isEmpty()) {
				stack2.push(stack1.pop());
			}
		}
		return stack2.pop();
	}

	public static void main(String[] args) {
		TwoStack stack = new TwoStack();
		stack.push(1);
		stack.push(2);
		System.out.println(stack.pop());
		stack.push(3);
		stack.push(4);
		System.out.println(stack.pop());
		System.out.println(stack.pop());
		stack.push(5);
		System.out.println(stack.pop());
		System.out.println(stack.pop());
	}

}
